I'm going from memory so take with dose of salt. Metformin does a whole bunch of things. Lots and lots of research on this stuff. It is reported to increase insulin sensitivity and slow glucose release from the liver via glycogen stores. It acts through modulation of CBP cascade modulation that connects liver glycogen/glucose release to pancreatic insulin secretion. This stuff has been out since the 1950s with a good clinical record. It seems to decouple a pathologized feedback loop that occurs in diabetes, basically increasing insulin sensitivity and decreasing blood glucose. It seems to have a lot of potentially positive impact on blood markers. Personally I was thinking of using it but pulled the plug. My A1c is pretty much perfect and blood lipids look pretty good so I convinced myself that it wasn't worth it to drastically change my energy metabolism drastically. At this point I would rather manipulate kcals and carbs to shock insulin sensitivity. It's probably a better practice since conscientious nutrition is probably the best medicine.

I think your logic is good if you are a healthy, non-diabetic person. My approach has evolved from more is better to use as few aids as possible to get the result you want.Why invite trouble? You end up taking meds to control meds.